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The discovery that hundreds of stars are rapidly moving together in long, looping orbits around the center of our galaxy has been announced by a team of scientists including a Penn State astronomer and others collaborating in the Sloan Digital Sky Survey III (SDSS-III).

"The stars near the nucleus of the Milky Way appear to form a bar-like structure thousands of light years in size," said Donald Schneider, a distinguished professor of astronomy and astrophysics at Penn State and coauthor of the study. "In this investigation, we were able to accurately measure the motions of a set of stars located in the galaxy's bar and to gain some insight into the dynamics of the central, dense regions of the Milky Way." Schneider is the survey coordinator and scientific publications coordinator for the SDSS-III.

For the past 5 billion years, the expansion of the universe has been powered by a mysterious repulsive force known as dark energy. Now, thanks to a new technique for measuring the three-dimensional structure of the distant universe, scientists in an international team within the Sloan Digital Sky Survey (SDSS-III), including an astronomer at Penn State, have made the first measurement of the rate of this cosmic expansion as it was just 3 billion years after the Big Bang. "Observations in the past 15 years have revealed that the expansion rate of the universe is accelerating," said Donald Schneider, Distinguished Professor of Astronomy and Astrophysics at Penn State, a coauthor of the study. "Most cosmological models predict that when the universe was young, dark energy had little influence on the expansion; at that time the evolution of the large-scale structure of the universe was dominated by gravitation, which is an attractive force that acted to slow the expansion. The new SDSS-III observations are an important probe of this early era."

The Sloan Digital Sky Survey III (SDSS-III), an international collaboration that includes Penn State astronomers, has produced the largest-ever three-dimensional map of massive galaxies and distant black holes. The new map will help to explain the mysterious "dark matter" and "dark energy" that scientists know makes up 96 percent of the universe. The map is the first in a series planned during a six-year project that will fully expand into three dimensions the largest-ever 2-D image of the sky, which the SDSS-III released early last year.

New evidence that will help to answer long-standing questions about the history of stars in the disk of our galaxy is being released this week at a meeting of the American Astronomical Society by a team that includes a Penn State astronomer. The research reveals some stars with orbits that take them to interesting places and that reveal interesting stories about how these stars were formed.

Donald Schneider, Head of Penn State's Department of Astronomy and Astrophysics, is one of the coauthors of the study. The study uses data from the Sloan Digital Sky Survey (SDSS), which has been mapping the stars in our galaxy for more than a decade. "The SDSS results are providing another window into the structure and history of our galaxy," said Schneider, who is the SDSS Survey Coordinator. More information is online at www.science.psu.edu/news-and-events/2012-news/Schneider1-2012.

A powerful new tool for probing the structure of our galaxy has been developed by astronomers associated with the Sloan Digital Sky Survey, including two Penn State astronomers. The new tool is an infrared spectrograph for the Apache Point Observatory Galactic Evolution Experiment (APOGEE). Over the next three years, APOGEE's initial census of the chemical constitution and motion of more than 100,000 stars across the Milky Way will bring together data on stars with ages spanning nearly the full age of the universe.

Scientists from the Sloan Digital Sky Survey (SDSS-III) collaboration, including an astronomer at Penn State, have created the largest-ever three-dimensional map of the distant universe by using the light of the brightest objects in the cosmos to illuminate ghostly clouds of intergalactic hydrogen. The map provides an unprecedented view of how the universe looked 10 billion years ago.

The Sloan Digital Sky Survey-III (SDSS-III) recently released the largest digital color image of the sky ever made, and it is free to all. The image has been put together over the last decade from millions of 2.8-megapixel images, creating a color image of more than a trillion pixels. This terapixel image is so big and detailed that 500,000 high-definition TVs would be needed to view it at its full resolution.

Penn State is one of three Pennsylvania institutions, along with the University of Pittsburgh and Carnegie Mellon University, that have scientists involved in SDSS-III.

Penn State University has become a participant in the Sloan Digital Sky Survey-III (SDSS-III), a six-year project that will expand our knowledge in fields ranging from the planets outside our solar system to the large-scale structure and evolution of the universe. "The SDSS-III is investigating some of the currently most compelling scientific questions," said Lawrence Ramsey, head of Penn State's Department of Astronomy and Astrophysics. "This is a great opportunity for Penn State faculty and students."

An international team of scientists, led by Penn State Distinguished Professor Donald Schneider, has announced its completion of a massive census in which they identified the quasars in one quarter of the sky. "Quasars are hundreds of times more luminous than our entire galaxy, yet they generate this tremendous power in regions similar in scale to that of our much smaller solar system," said Schneider. "The best explanation of this extraordinary phenomenon is that we are witnessing the light energy emitted by material falling into black holes with masses of hundreds of millions of times, or even more than a billion times, that of our Sun."

The most ambitious attempt yet to trace the history of the universe has seen "first light." Two Penn State scientists, Professors of Astronomy Niel Brandt and Donald Schneider, are members of the Baryon Oscillation Spectroscopic Survey (BOSS), a part of the Sloan Digital Sky Survey III (SDSS-III), which has begun a quest to collect electromagnetic-radiation spectra for 1.4 million galaxies and 160,000 quasars by 2014. "These observations should provide quite accurate measurements of the expansion history of the universe, and thus should reveal the relative importance of ordinary matter, dark matter and dark energy over a wide range of cosmic time," Brandt said.